Question: Simplify the following expression: $k = \dfrac{t}{7} + \dfrac{9t}{8}$
Answer: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $7$ and $8$ $\lcm(7, 8) = 56$ $ k = \dfrac{8}{8} \cdot \dfrac{t}{7} + \dfrac{7}{7} \cdot \dfrac{9t}{8} $ $k = \dfrac{8t}{56} + \dfrac{63t}{56}$ $k = \dfrac{8t +63t}{56}$ $k = \dfrac{71t}{56}$